Table 1 Characteristics of included studies
First author | Number of centres | Study type | Country of population | Year of publication | Study time period | Mean age | Time points/time windows | Cut-off(s) | Time from HFNC initiation to intubation | Definition of HFNC success/failure | Number of HFNC failures | Number of HFNC successes | Number of included patients |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Hu | Multicentre | Retrospective | China | 2020 | 2020 | 64 | 6Â h | 5.55 | NR | HFNC withdrawal with improved oxygenation, not requiring NIV/IMV, discharged alive | 40 | 65 | 105 |
Bruna | Single-centre | Prospective | Chile | 2022 | 2020 | 63.3 | 12Â h | 6.80, 7.30 | NR | Intubation, death | 16 | 25 | 41 |
Talpos | Single-centre | Retrospective | Belgium | 2022 | 2020 | 70 | 0-24Â h | 5.63 | NR | IMV | 31 | 21 | 52 |
Duan | Multicentre | Retrospective | China | 2021 | 2020 | 67.4 | 1 h, 2 h, 4 h, 8 h, 12 h, 24 h | 5.49, 5.63, 5.94, 6.25, 7.17, 7.93 | Median 41 IQR (19–152) hours | NIV, IMV | 29 | 37 | 66 |
Chandel | Multicentre | Retrospective | USA | 2021 | 2020 | 57 | 2Â h, 6Â h, 12Â h, 2-12Â h | 3, 3.41, 3.46, 3.67, 4.57 | NR | HFNC successfully weaned | 108 | 164 | 272 |
Kim | Multicentre | Retrospective | Korea | 2022 | 2020 to 2021 | 70 | 1Â h | 8.54 | NR | Intubation, IMV | 70 | 63 | 133 |
Ferrer | Single-centre | Prospective | Spain | 2021 | 2021 | 64.5 | 1Â h, 6Â h, 12Â h, 24Â h | 5.25, 5.27, 5.35, 5.41 | NR | IMV, NIV, death | 47 | 38 | 85 |
Calligaro | Multicentre | Prospective | South Africa | 2020 | 2020 | 51.3 | 6 h | 2.2, 2.7, 3.7 | Median 2 IQR (0.5–5) days | Intubation, death | 156 | 137 | 293 |
Myers | Multicentre | Retrospective | USA | 2022 | 2020 | 61.4 | 12 h | 3.85, 4.88 | Median 83.5 IQR (27.8–178.9) hours | IMV | 585 | 1262 | 1847 |
Metwaly | Single-centre | NR | NR | 2021 | NR | NR | 24Â h | 5.2 | NR | HFNC weaned with improved oxygenation | 15 | 60 | 75 |
Hamou | Single-centre | Retrospective | France | 2022 | 2020 to 2021 | 67 | 6Â h | 1.96 | NR | Intubation | 78 | 36 | 114 |
Vega | Multicentre | Retrospective analysis of prospectively collected data | Argentina and Italy | 2022 | 2020 | NR | 2 h, 6 h, 12 h, 24 h | 5.1, 5.8, 5.99, 8.36 | Median 2 IQR (1–3) days | IMV, death | 35 | 85 | 120 |
Blez | Single-centre | Prospective | France | 2020 | 2020 | NR | 0.5Â h | 3.8 | NR | IMV within 7Â days of HNFC | 16 | 14 | 30 |
Zucman | Single-centre | Retrospective | France | 2020 | 2020 | 55.3 | 0-4Â h | 5.37 | NR | HFNC successfully weaned | 39 | 21 | 60 |
Takeshita | Single-centre | Retrospective | Japan | 2022 | 2021 | 57.9 | NR | 5.55 | NR | IMV | 14 | 22 | 36 |
Burnim | Multicentre | Retrospective | USA | 2021 | 2020 | 63 | 5-12Â h | 3.85 | NR | IMV | 266 | 196 | 462 |
Fernando Valencia | Single-centre | Retrospective | Columbia | 2021 | 2020 | 62.5 | 2Â h | 5.6 | NR | Intubation, death due to COVID-19 | 152 | 93 | 245 |
Gaspic | Single-centre | Retrospective | Croatia | 2021 | 2020 to 2021 | 65.7 | NR | 4.12 | NR | In-hospital death | 42 | 60 | 102 |
Kucuk | Single-centre | Retrospective | Turkey | 2022 | 2020 to 2021 | 66.7 | 1Â h | 3.81 | NR | IMV, death | 52 | 33 | 85 |
Panadero | Single-centre | Retrospective | Spain | 2020 | 2020 | 58.9 | 2-6 h | 4.94 | Median 2 IQR (1–4) days | Intubation | 21 | 19 | 40 |
Aparicio | Single-centre | Retrospective analysis of prospectively collected data | Spain | 2020 | 2020 | 60.8 | 12Â h | 5.57 | NR | Not requiring NIV, IMV, ECMO; no death; within 28Â days of HFNC | 6 | 15 | 21 |
Tzouanatou | Single-centre | Prospective | Greece | 2022 | 2021 | 57 | 6 h | 4.79 | Mean 4.48 days | Sustained severe hypoxemia (PaO2/FiO2 < 100) requiring IMV and ICU admission | 23 | 46 | 69 |
Wojcik | Single-centre | Prospective | Poland | 2021 | 2021 | 60.7 | 0-12Â h | 3.85, 4.88 | Survivors: Median 1Â day Non-survivors: Median 3Â days | Not requiring intubation | 63 | 50 | 113 |
Xu | Multicentre | Retrospective | China | 2020 | 2020 | 63.2 | 0-4Â h | 5.31 | NR | IMV within 7Â days of HFNC initiation | 147 | 177 | 324 |